#include <iostream>
#include <vector>
using namespace std;

const int N = 10;
vector<int>f(N + 1);
int n;
int main()
{
    cin >> n;
    for (int i = 1; i <= n; i++) {
        f[i] = 1;
        for (int j = 1; j < i; j++) {
            f[i] += f[j];
        }
    }
    cout << f[n] << endl;
    return 0;
}